Treated leather.



use the same.

CARL E. SCHMIDT, 0F DETROIT, MICHIGAN.

TREATED LEATHER.

No Drawing. Z

' Specification of Letters Eatent. Application filed March 16, 1910. Serial No. 549,627.

Patented J uly 11, 913.

To all whom it may concern:

Be it known that I, CARL E. SCHMIDT, Who am a citizen of the United States, residing at Detroit, county of Wayne, State of Michigan, have invented a certain new and useful Improvement in- Compounds for 'Treated Leather, and declare the following to be a full, clear,and exact description of the same,such as will enable others skilled in the art to which it pertains to make and This invention relates to treated leather, and has for its object an improved article which, as an incident to its preparation, is impregnated with a compound, which, while in no way injuring it either as to finish or lastingqualities,- contains a normally latent .indicating element,- which, when touched with an external body, preferably porous, such as blotting papenwhich has been saturated with a chemical reagent to'the latent indicating element, caus'es a change in the 'color thereof, such as from white to pink,

thereby proving'thatthe leather has been. treated by acertain process, whose products, have attained an enviable reputation for their wearing qualities. p A- welldmowncompound for treating leather, previousto its manufacture idto shoes and the like, consists of approximately equal parts of white of egg, albumen, gelatin, and gum tragacanth. The proportions it may be varied-to accord with the exact finish thatit is desired to impartto the leather; and similarly for some one or the other of said above named constituents, Irish moss, glue and'gelatimblood, milk, or casein may be substituted; all of these are well known. Shellac is also frequentl used. When, however, a particulancom ination. of such elements has resulted in imparting a par ticular quality to leather, upon' which a manufacturer has succeeded in building up a considerable trade, and which he hasparticularly designated heretofore by stamping on one face of the leather, it has been necessary, in order to determine whether the leather of a shoe is'of that articular make, as may be claimed, to part y turn it'inside out, and

partly cut it open as regards its lining.

I have discovered that if a small proportion, say one per cent. or less, of phenolphthalein be added to the compound of several other parts, chosen from those above named, either when the leather is first coated or treated and as a part of the coating com-.

' wit pound, or after a compound of already well known parts is applied, as a separate application, very preferably, however, when the leather is first treated, the finish imparted to the leather is not only desirable, but the en tire surface of the leather acquires the qual-' ity of responding chemically when touched causingthe same to turnpinln effect is No badfor instance, a piece/of white blottingpaper which has been'saturated with an'al-{ ka ine solution, preferably ammonia, by

produced by thus touching the leather. If, however, the'leatherasfinishedi does not contain this phenolphthalein-or some, such equivalent therefor as methylora.

Congo red, or litmus, no coloring 'efiect ad d be produced on the blotting paper, and'the spurious character of the-leather would be l thus established. 7 As stated, I do not desire toconfine myself to exact proportions," nor merely-to the use of phenolphthalein as the impregnating agent for the leather, nor to ammonia as the innso 1 pregnating agent for the testing blotter, inv

fact, with some of the equivalent substances for phenolphthalein, l have found that an' acid may be acceptably used instead of ammonia to saturate the testing blotter,

1. As a new article or manufacture,

leatherimprgnatedw th a solution of already known finishing substances, and a desired proportion of a latent impregnating medium having'the quality of combining;

with an alkaline solution, with which an external carrying body brought into contact therewithis saturated, to cause a'change ofa color thereof, substantially as described.

2. As a new .article of manufacture,

leather impregnated with a'combination of substances which not'only give to it the de sired finish, but also impart to it the quality of chemically indicatin the applicatiouof a chosen testing agent y causing a'change.

inthe color thereof when brought into contact with the scribed. i v

3. As a new article of manufacture,

leather impregnated with a plurality of al- 'buminou's elements in. desired proportions, gum

tragacanth, and phenolphthalein, whereby the color of an alkaline saturated article brought into contact therewith is c'aused't'o change, without permanent effect upon the leather, substantia 1y as described.

ans a new article of manufacture,

leather, substantially as deloo leather impregnated with already known finishing substances and a commmgled indicating compound which remains latent in the leather until the same is brought into contact with a body carrying a chemical reagent, and which then indicates its presence in. the leather, by causing a change in the 5. As a new article of manufacture, leather impregnated with a plurality of albuminous elements and a eommingled latent mdlcating element, whose presence therein is indicated by the change in color imparted to a body carrying a reagent to said inclicating element brought into contact with the I leather,'substantially as described.

6. As a new article of manufacture, leather lmpregnated with a commlngled solutlon of known finishing elements and a V latent indicating element adapted to indicate its presence in the leather by causing a color change in an article saturated with a chemically reagent element which is brought into contact therewith, substantially as described.

7. An article of manufacture, comprising leather impregnated with a compound of with a body saturated with a selected chemical reagent, by causing a change in the color ofv that part of the saturated body brought into contact with the leather, substantially as described 8. Aii 'icl of manul lacture, comprising leather impregnated with a plurality of albuminous elements and a commingled quantity of phenolphthalein, said phenolphthalein beingnormally latent therein, and being adapted to make its presence known by causing a change in the color of a. foreign body saturated with an alkaline solu- 'tion when the same is brought into contact therewith, substantially as described.

In testimony whereof I sign this specification in the presence of two witnesses.

CARL E. SCHMIDT.

Witnesses:

VIRGINIA O. SPRATT, WILLIAM M. SWAN. 

